Feeding device and object driving device

ABSTRACT

To provide a feeding device capable of driving an object with high accuracy while holding the object and controlling its attitude and capable of improving durability by separating a holding device and a driving device from each other, and an object driving device. The feeding device movably disposed through a cover device to face a work region shielded by the cover device, for holding an object, includes: a first rotary saddle that is rotatable about a first axis; a second rotary saddle disposed on the first rotary saddle and rotatable about a second axis perpendicular to the first axis; a holding device that holds the object; a first driving device disposed outward of the cover device with regarding the work region to rotate the first rotary saddle; and second driving device disposed outward of the cover device with respect to the work region to rotate the second rotary saddle.

BACKGROUND

1. Field of the Invention

The present invention relates to a feeding device and an object drivingdevice, and more particularly, to a feeding device which includes firstand second rotary saddles for rotatably supporting an object, and anobject driving device.

2. Description of the Related Art

A high-pressure cleaning machine is used for cleaning of products,particularly mechanical parts such as automobile parts. Thehigh-pressure cleaning machine directs onto an object to be cleaned(hereinafter referred to as the “workpiece”) high-pressure jets obtainedby pressurizing cleaning liquid to a high pressure and jetting it fromnozzles. At this time, cutting oil, chips or other foreign matters, orburrs on a work surface are removed by an impact force and cleavageforce generated when the high-pressure jets impinge on the work surface.Because the jets change their orientation upon contact with the worksurface to flow along the work surface, the high-pressure cleaningmachine is suitable for cleaning and deburring of mechanical partshaving outer surfaces with complicated shapes (for example, JapanesePublished Unexamined Patent Application No. 2004-141811 (claim 1, FIGS.1 to 6) and U.S. Pat. No. 8,034,191 (FIGS. 9 to 15)).

The cleaning apparatus disclosed in the Japanese Published UnexaminedPatent Application No. 2004-141811 performs cleaning by sequentiallypositioning while moving nozzles so that the nozzles face a singleworkpiece hole. The cleaning apparatus disclosed in the U.S. Pat. No.8,034,191 performs cleaning by controlling the attitude of the workpiecewhile holding the workpiece with a multi-joint robot so that theworkpiece is directed toward nozzles.

However, there is a problem in that, when the nozzles are moved in thesame manner as the cleaning apparatus disclosed in the JapanesePublished Unexamined Patent Application No. 2004-141811 (claim 1, FIGS.1 to 6), the construction for ensuring the sealing performance iscomplicated and the flexibility in design is lowered in the case ofsupplying an high-pressure cleaning liquid to the nozzles.

In the cleaning apparatus disclosed in the U.S. Pat. No. 8,034,191(FIGS. 9 to 15), there is a problem in that, because the multi-jointrobot holds the workpiece and directs it toward the nozzles, controloperation is complicated and it is difficult to improve the positioningaccuracy, repeatability, or locus accuracy. In the case of cleaning ordeburring with high-pressure jets, the high-pressure jets need to strikethe workpiece exactly along its outline. If the positioning accuracy,repeatability, or locus accuracy is low, the effect of cleaning ordeburring with high quality is hard to obtain.

Furthermore, the multi-joint robot is directly splashed with thehigh-pressure water jetted from the nozzles or indirectly splashed withthe high-pressure water bounced off the workpiece. Because themulti-joint robot is a precision component, unfortunately, it is likelyto be damaged due to contact with high-pressure water.

SUMMARY

Accordingly, an object of the present invention is to provide a feedingdevice which is capable of driving an object with high accuracy whileholding the object and controlling its attitude and capable of improvingdurability by effectively separating a holding device and a drivingdevice from each other, and an object driving device.

In view of the above-described problems, the present invention isconstituted as follows.

A first aspect of the present invention provides a feeding devicemovably disposed through a cover device so as to face a work regionshielded by the cover device, for holding an object and controlling anattitude of the object. The feeding device includes: a first rotarysaddle that is rotatable about a first axis; a second rotary saddle thatis disposed on the first rotary saddle and rotatable about a second axisin a direction different from the first axis; a holding device that isdisposed on the second rotary saddle to hold the object; a first drivingdevice that is disposed outward of the cover device with respect to thework region to rotate the first rotary saddle; and a second drivingdevice that is disposed outward of the cover device with respect to thework region to rotate the second rotary saddle.

It should be noted that in the following description, the term “work”includes a wide range of operation, such as machining with a tool,coating, or cleaning. It should be also noted that the term “cleaning”includes a wide range of operation, such as a work and processingperformed by jetting high-pressure jets (such as cleaning liquid, water,and air) from nozzles, which is not particularly limited, but can alsobe used for, for example, removal of burrs formed by hole drilling ormilling, or air blowing.

According to the first aspect of the present invention, the feedingdevice is movably disposed through the cover device so as to face thework region shielded by the cover device. Thus, the first and seconddriving devices can be easily shielded from the work region by the coverdevice. Therefore, the flexibility in design of the moving device formoving the feeding device is improved and the linear moving device iseasily adopted. Furthermore, the driving system and transmission systemof the feeding device can be disposed at the inside or rear of thefeeding device, and therefore are shielded from the work region by thefeeding device and the cover device. Thus, the driving system isprevented from being damaged due to contact with jets or vapors ofcleaning liquid.

Moreover, the first and second rotary saddles allows the biaxialrotation of the object for its attitude control. Therefore, by freelyadjusting the angle with respect to the object, suitable operation canbe performed.

Consequently, the feeding device according to the first aspect of thepresent invention is flexibly adaptable to a wide variety of objects.

In this manner, the feeding device according to the first aspect of thepresent invention can linearly drive the object with high accuracy whileholding the object and controlling its attitude and can improve thedurability by effectively separating the holding device and the drivingdevice.

Furthermore, preferably, the holding device has: a fluid pressurecylinder that holds the object; and a fluid supply unit that suppliespressure fluid from a fluid supply source to the fluid pressurecylinder. The fluid supply unit includes: a first fluid supply rotaryjoint that is disposed on the first rotary saddle; a second fluid supplyrotary joint that is disposed on the second rotary saddle; a first fluidpassage that supplies pressure fluid from the fluid supply source to thefirst fluid supply rotary joint; a second fluid passage that suppliespressure fluid from the first fluid supply rotary joint to the secondfluid supply rotary joint; and a third fluid passage that suppliespressure fluid from the second fluid supply rotary joint to the fluidpressure cylinder.

With this constitution, the first and second fluid supply rotary jointsallow the reliable supply of fluid to the fluid pressure cylinder evenwhen the first and second rotary saddles rotate.

Furthermore, the fluid supply routes are rotatably installed, therebypreventing the liquid passages from being subjected to twisting orbending. Because the liquid passages are not subjected to twisting orbending, the liquid passages can be made of hard material such as ametal material. Therefore, the liquid passages can be prevented fromdamage and corrosion and improved in stiffness and durability.

A second aspect of the present invention provides an object drivingdevice which has the feeding device according to the first aspect of theinvention, a moving device for movably supporting the feeding device,and a bed for supporting the moving device. The moving device includes:a horizontal movement guide mechanism that is placed on the bed; amoving column that is movably supported by the horizontal movement guidemechanism; an X-axis driving device that horizontally moves the movingcolumn; a vertical movement guide mechanism that is disposed on themoving column; a Z-axis saddle that is movably supported by the verticalmovement guide mechanism; and a longitudinal movement guide mechanismthat is disposed on the Z-axis saddle to longitudinally movably supportthe feeding device. The moving device is disposed outward of the coverdevice with respect to the work region.

According to the second aspect of the present invention, the horizontalmovement guide mechanism, the vertical movement guide mechanism, and thelongitudinal movement guide mechanism are provided, thereby allowing thefeeding device to move linearly in triaxial directions with highaccuracy by driving one axis while fixing the other two axes and move ona free locus by combining the triaxial movements.

In this manner, the object driving device according to the second aspectof the invention allows the feeding device to move freely in thetriaxial directions. It is therefore possible to freely move the objectto the work region with the moving device while holding the object withthe holding device and controlling its attitude.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be described in detail basedon the following drawings, in which:

FIG. 1 is a perspective view of a cleaning apparatus according to anembodiment of the present invention as seen from the front right side;

FIG. 2 is a perspective view of the cleaning apparatus according to theembodiment of the present invention as seen from the rear right side;

FIG. 3 a schematic diagram showing the construction of a feeding deviceaccording to the embodiment of the present invention;

FIG. 4 is a sectional view showing the construction of the feedingdevice according to the embodiment of the present invention;

FIG. 5 is a hydraulic circuit diagram showing a flow passage ofhigh-pressure cleaning liquid in the cleaning apparatus according to theembodiment of the present invention;

FIGS. 6A and 6B show the construction of a cleaning tank of the cleaningapparatus according to the embodiment of the present invention, whereinFIG. 6A is a perspective view thereof as seen from the rear right side,and FIG. 6B is a perspective view thereof as seen from the front leftside; and

FIGS. 7A and 7B are perspective views each showing a state in which acleaning lance is used in the cleaning apparatus according to theembodiment of the present invention, wherein FIG. 7A shows the statebefore insertion of a workpiece into the cleaning lance, and FIG. 7Bshows the state after insertion of the workpiece into the cleaninglance.

DETAILED DESCRIPTION

A feeding device 40 according to an embodiment of the present invention,for example in the case of being mounted on a cleaning apparatus 10,will be described with reference to FIGS. 1 to 7.

As shown in FIG. 1, the cleaning apparatus 10 mounted with the feedingdevice 40 according to the embodiment of the present invention cleans aworkpiece W, serving as an object, by jetting cleaning liquid fromcleaning nozzles 22, serving as nozzles, disposed in a cleaning region Eas a work region. The workpiece W is moved to the cleaning region E bythe feeding device 40 for cleaning.

The cleaning apparatus 10 includes an orthogonal moving device 70,serving as a moving device, on a bed 11 to the rear, and a cleaningchamber 15 forwardly. The orthogonal moving device 70 is numericallycontrolled. The cleaning chamber 15 includes a large machine-chamberopening 18 in the rear (see FIG. 2). The machine-chamber opening 18 iscovered with a cover device 14 that is vertically and horizontallymovable. Only a leading end (feeding head) of the feeding device 40disposed on the orthogonal moving device 70 penetrates through the coverdevice 14 into the cleaning chamber 15 located forward. A first rotarysaddle 59 is disposed on the leading end (feeding head) of the feedingdevice 40, and a second rotary saddle 47 is disposed on the first rotarysaddle 59. A coupling device 48 composed of a joint mechanism (notshown), etc., which is removably constructed, is disposed on the secondrotary saddle 47. The coupling device 48 removably couples a holdingdevice 17 on the second rotary saddle 47.

A workpiece driving device 13 serving as a target driving device isprovided with the feeding device 40, and the orthogonal moving device 70that movably supports the feeding device 40, serving as a moving device.

It should be noted that the following description is given, it beingassumed, for purposes of description, that the horizontal direction isthe X axis, the longitudinal direction is the Y axis, and the verticaldirection is the Z axis as seen from an operator (not shown) in front ofthe cleaning chamber 15. However, the directions or axis names of thecleaning apparatus 10 should not be taken as a limitation of the presentinvention.

The bed 11 is a solid base and supports the cleaning chamber 15, theorthogonal moving device 70, or the like on its upper portion.Furthermore, the bed 11 includes a waste liquid passage (not shown) forsending cleaning liquid overflowing or jetted from the cleaning chamber15, chips, machining oil or other foreign matters generated from theworkpiece W, and burrs falling from the workpiece W to a cleaning liquidtank. Further, the bed 11 fixes a control panel (not shown) forcontrolling the orthogonal moving device 70, a high-pressure pump,various valves, etc., and a synchronizing device 95 serving as anumerical control device.

Referring to FIG. 2, the workpiece driving device 13, serving as atarget driving device, and the orthogonal moving device 70 will bedescribed.

The workpiece driving device 13 includes: the feeding device 40; theorthogonal moving device 70 that movably supports the feeding device 40;and the bed 11 that supports the orthogonal moving device 70.

Horizontal movement guide mechanisms 73 are arranged in parallel on thebed 11. A frame 12 surrounding the orthogonal moving device 70 isdisposed upright on an upper surface of the bed 11. An X-axis drivingdevice 86 includes a first X-axis driving device 71 disposed on the bed11, a second X-axis driving device 75 disposed at an upper portion ofthe frame 12, and the synchronizing device 95. The first and secondX-axis driving devices 71 and 75 are installed in parallel in thehorizontal (left-right) direction to synchronously drive a moving column78 in the X-axis direction with the synchronizing device 95.

The first X-axis driving device 71 is composed of a first X-axis ballscrew 74 and a first X-axis motor 72 that rotates the first X-axis ballscrew 74. A nut (not shown) of the first X-axis ball screw 74 is fixedto a bottom of the moving column 78. The second X-axis driving device 75is composed of a second X-axis ball screw 77 and a second X-axis motor76 that rotates the second X-axis ball screw 77. A nut (not shown) ofthe second X-axis ball screw 77 is fixed to a front upper portion of themoving column 78.

The orthogonal moving device 70 moves the workpiece (see FIG. 1) andtherefore its movable range is very large. Furthermore, because theorthogonal moving device 70 moves the large-sized feeding device 40 tobe described later, the moving column 78 is also large. Therefore, theload moment and inertia on the horizontal movement guide mechanisms 73and the X-axis driving device 86 are very large. Also, the distortioncaused by the movement of the moving column 78 becomes large. However,by driving lower (bottom) and upper portions of the moving column 78with the separate X-axis driving devices (71 and 75) and synchronizingthem, the distortion of the moving column 78 is suppressed and themoment and load inertia on each driving device can be reduced.

The moving column 78 moves along the X-axis direction and includes the Zaxis as a vertical axis. A Z-axis driving device is composed of verticalmovement guide mechanisms 81 that are arranged in parallel along thevertical direction on the moving column 78, a Z-axis ball screw 80, anda Z-axis motor 79 that rotates the Z-axis ball screw 80.

A Z saddle 85 moving vertically on the Z axis includes a Y-axis drivingdevice in a direction perpendicular to the X axis and the Z axis. TheY-axis driving device includes a longitudinal movement guide mechanism83, a Y-axis motor 82, a Y-axis ball screw (not shown), and a Y saddle84 that is movably supported by the longitudinal movement guidemechanism 83. The feeding device 40 is disposed on the Y saddle 84.

A safety cover (not shown) is disposed outside the frame 12 to shieldfrom the outside the space (hereinafter referred to as the “machinechamber”) where the orthogonal moving device 70 moves. The machinechamber is shielded from the cleaning chamber 15 including the cleaningregion E by the cover device 14, thereby blocking the entrance ofcleaning liquid from the cleaning chamber 15.

A telescopic or bellows cover is used as the cover device 14.

Referring to FIGS. 3 and 4, the feeding device 40 will be described.FIG. 3 schematically shows a power transmission system and a fluid pipeconnection path of the feeding device 40. FIG. 4 is a longitudinalsectional view of the feeding device 40. FIG. 4 illustrates the secondrotary saddle 47, with the first rotary saddle 59 rotated 90°.

The feeding device 40 is disposed on the Y saddle 84 of the orthogonalmoving device 70 to move freely in triaxial directions with theorthogonal moving device 70. The feeding device 40 is disposed throughthe cover device 14, rear and inner portions thereof being isolated fromthe cleaning chamber 15. The orthogonal moving device 70 movablysupporting the feeding device 40 is disposed at the rear of the coverdevice 14, thereby preventing the corrosion of the orthogonal movingdevice 70 due to the environment in the cleaning chamber 15.

The feeding device 40 includes a feed base 55 that is a base memberhaving a hollow cylindrical shape; the first rotary saddle 59 that isrotatably disposed forward of the feed base 55 to rotate about a firstaxis 87; and the second rotary saddle 47 that is disposed on the firstrotary saddle 59 to rotate about a second axis 88 perpendicular to theaxis of rotation of the first rotary saddle 59. The coupling device 48for coupling the holding device 17 is disposed at a tip of the secondrotary saddle 47. A housing 50 is fixed to the rear of the feed base 55.A servomotor 49, serving as a first driving device, and a servomotor 41,serving as a second driving device, are fixed to the housing 50.

The second axis 88 is made perpendicular to the first axis 87, therebyallowing easy calculation of the attitude of the workpiece W held by theholding device 17.

It should be noted that the first axis 87 and the second axis 88 onlyneed to be different in direction, and the angle therebetween may be,for example, 135°. The first axis 87 need not be coaxial with the feedbase 55, and the center angle formed by the first axis 87 and the feedbase 55 may be set to be, for example, 135°.

Furthermore, as for the servomotors 49 and 41, a motor with a brake or afluid pressure rotating cylinder may be used in place of the servomotor.In this case, a mechanical stopper for rotation restriction is usedtogether. An air cylinder, which uses compressed air being acompressible fluid as pressure fluid, or a hydraulic cylinder, whichuses hydraulic pressure being a non-compressible fluid, may be used asthe fluid pressure rotating cylinder.

The output of the servomotor 49 is transmitted to a gear 52 by acoupling 51, and then transmitted to a journaled first transmissionshaft 54 by the gear 52 and a gear 53. A small-diameter gear 56 is fixedto a leading end of the first transmission shaft 54 and has a meshingengagement with a large-diameter gear 57. The large-diameter gear 57 isfixed to an input shaft 58 a of a planetary gear 58 serving as a firstreduction gear. The rotation of the servomotor 49 is transmitted to theplanetary gear 58 through the first transmission shaft 54 anddecelerated to be output from an output shaft (first output shaft) 58 bserving as a hollow shaft. The first rotary saddle 59 is journaled tothe output shaft 58 b, with a second transmission shaft 43 as itsrotating shaft. The small-diameter gear 56, the large-diameter gear 57,and the planetary gear 58 constitute a first reduction gear.

The planetary gear 58 provided at the end of the power transmissionsystem of the servomotor 49 allows a reduction in backlash of the gearmechanisms 52, 53, 56, and 57 included in the transmission system.Therefore, rotational play of the first rotary saddle 59 is reduced.Thus, the attitude of the workpiece W held by the holding device 17 canbe kept with high accuracy. Further, because the first transmissionshaft 54 transmits the power before deceleration, its cross-sectionalarea can be made small. After deceleration by the planetary gear 58, thetorque increases. However, the output shaft 58 b and the first rotarysaddle 59 are directly connected, and thus the transmission system canbe easily configured.

It should be noted that a cycloid reduction gear (see Japanese PublishedUnexamined Patent Application No. 2010-32038), an eccentric differentialgearbox (see Japanese Published Unexamined Patent Application No.2012-506005), or an eccentric oscillation type gear device (see JapanesePublished Unexamined Patent Application No. 2010-91073), may be used inplace of the planetary gear 58 serving as a first reduction gear. Thecycloid reduction gear is suitable because it can decelerate the drivingforce which is large relative to its size. Furthermore, the firstreduction gear mechanism any reduction gear may be adopted in place ofthe small-diameter gear 56, the large-diameter gear 57, and theplanetary gear 58 as long as it has a hollow output shaft, allows thesecond transmission shaft 43 to penetrate into the hollow output shaft,and has an input shaft parallel to the output shaft.

The output of the servomotor 41 is transmitted directly to the secondtransmission shaft 43 through a coupling 42. The second transmissionshaft 43 is journaled coaxially with the first rotary saddle 59 andpenetrates the center of the hollow output shaft 58 b of the planetarygear 58. Moreover, the second transmission shaft 43 is disposed at thecenter of the feed base 55 to serve as the rotating shaft of the firstrotary saddle 59. A small-diameter bevel gear 44 is fixed to a leadingend of the second transmission shaft 43. A large-diameter bevel gear(second bevel gear) 45 in mesh with the small-diameter bevel gear (firstbevel gear) 44 is fixed to an input shaft 46 a of a planetary gear 46serving as a second reduction gear. The rotation of the servomotor 41 isconverted to a perpendicular transmission direction by the bevel gears44 and 45. This rotation is decelerated by the planetary gear 46 to beoutput from the hollow output shaft (second output shaft) 46 b. Thebevel gears 44 and 45 and the planetary gear 46 constitute a secondreduction gear mechanism. The second rotary saddle 47 having an umbrellashape is rotatably fixed to the output shaft 46 b in such a manner as topenetrate therethrough.

The input shaft 58 a and the output shaft 58 b of the planetary gear 58are formed as hollow shafts so that the second transmission shaft 43 iscoaxially disposed therein. Thus, the assembly accuracy of the powertransmission system can be improved. Also, the construction issimplified and production costs can be reduced.

The planetary gear 46 is provided on the output side of the bevel gears44 and 45, thereby allowing transmission of large torque to a smallspace. Furthermore, backlash of the bevel gears 44 and 45 is reduced inaccordance with the reduction ratio of the planetary gear 46, leading toa reduction in play of the second rotary saddle 47. Thus, the attitudeof the workpiece W held by the holding device 17 can be kept with highaccuracy. The second rotary saddle 47 is directly connected to theplanetary gear 46, thereby simplifying the construction of the feedingdevice 40.

The second transmission shaft 43, which is journaled in the feed base55, and the hollow output shaft 58 b are coaxially arranged, andfurther, the first rotary saddle 59 is disposed on the secondtransmission shaft 43. Thus, the transmission system with compact simplestructure can be obtained.

It should be noted that a reduction gear in which input and outputshafts are coaxial and the output shaft is a hollow shaft, as typifiedby the foregoing reduction gears, may be used in place of the planetarygear 46 as the second reduction gear.

It should be also noted that the first or second reduction gear isunnecessary if the output of the servomotor 49 or 41 is sufficientlylarge.

Referring mainly to FIG. 3, a fluid supply unit 96 that suppliespressure fluid from a fluid supply source 62 to a fluid pressurecylinder 68 will be described.

The fluid supply unit 96 includes: a first fluid supply rotary joint 61that is disposed on the first rotary saddle 59; a second fluid supplyrotary joint 60 that is disposed on the second rotary saddle 47; a firstfluid passage 64 that supplies pressure fluid from the fluid supplysource 62 to the first fluid supply rotary joint 61; a second fluidpassage 65 that supplies pressure fluid from the first fluid supplyrotary joint 61 to the second fluid supply rotary joint 60; and a thirdfluid passage 66 that supplies pressure fluid from the second fluidsupply rotary joint 60 to the fluid pressure cylinder 68.

On the side (i.e., leading end) of the first rotary saddle 59 on whichthe holding device 17 is disposed, the first fluid supply rotary joint61 is disposed coaxially with a rotating shaft of the first rotarysaddle 59. The first fluid supply rotary joint 61 is composed of: ashaft body 61 b that is fixed coaxially with the rotating shaft of thefirst rotary saddle 59; and a housing 61 a that is journaled to theouter periphery of the shaft body 61 b to rotate along with the firstrotary saddle 59.

On the side (i.e., rear end) of the second rotary saddle 47 opposite theholding device 17, the second fluid supply rotary joint 60 is disposedcoaxially with the second rotary saddle 47. The second fluid supplyrotary joint 60 is composed of: a housing 60 a that is fixed to thefirst rotary saddle 59; and a shaft body 60 b that is journaled to aninside of the housing 60 a to form a portion of the second rotary saddle47.

The fluid supply source 62 (see FIG. 3) is connected to a valve unit 63.The fluid supply source 62 supplies compressed air. The first fluidpassage (pipe) 64 allows the valve unit 63 and the shaft body 61 b ofthe first fluid supply rotary joint 61 to communicate with each other.The first fluid passage 64 extends through the inside of the feed base55 to a leading end of the feed base 55 and passes laterally to arotation space of the first rotary saddle 59 to be connected to thefluid supply rotary joint 61 (see FIG. 4). The second fluid passage 65passes through the inside of the first rotary saddle 59 from the housing61 a of the fluid supply rotary joint 61 to communicate with the housing60 a of the second fluid supply rotary joint 60. The third fluid passage66 passes through the shaft body 60 b and the inside of the secondrotary saddle 47 to communicate with a fluid coupling 67 of the couplingdevice 48.

It should be noted that the fluid to be supplied by the fluid supplysource 62 is not limited to compressed air, but may include any fluidthat functions as a driving source and does not contaminate theworkpiece W, the holding device 17, a cleaning tank 20, and the coverdevice 14.

A plurality of the first to third fluid passages 64, 65, and 66 areprovided for bringing various fluid devices disposed on the holdingdevice 17 into communication with the valve unit 63. The valve unit 63is an assembly of multiple directional control valves to select the flowpassage for each fluid supplied from the fluid supply source 62.

The rotating shafts of the two rotary saddles 59 and 47 disposedcoaxially with the fluid supply rotary joints 61 and 60, respectively,are connected by the first to third fluid passages 64, 65, and 66,thereby allowing supply of pressure fluid to the freely rotatable secondrotary saddle 47. The supplied pressure fluid is used as the drivingsource of the holding device 17 for holding the workpiece W.

Because the second fluid passage 65 and the third fluid passage 66 arefreely rotated by the fluid supply rotary joints 61 and 60, metal pipescan be used as the first to third fluid passages 64, 65, 66. Althoughthe leading end portion of the feeding device 40 moves inside thecleaning chamber 15 is subjected to high-pressure cleaning liquid andcleaning liquid vapor, greater durability can be given to the pipes bysupplying fluid pressure through the metal pipes.

The coupling device 48 including the fluid coupling 67 is disposed onthe leading end of the second rotary saddle 47. The coupling device 48is formed of the so-called “easy release joint” and has the function ofcoupling the second rotary saddle 47 and the holding device 17 at aprecise position and concurrently supplying pressure fluid to theholding device 17 with the fluid coupling 67.

The fluid coupling 67 has the function of supplying pressure fluid fromthe second fluid supply rotary joint 60 to the fluid pressure cylinder68 or the like when the coupling device 48 couples the holding device 17and the second rotary saddle 47, and shutting off the supply of pressurefluid when the coupling device 48 detaches the holding device 17 and thesecond rotary saddle 47 from each other.

By this construction, the holding devices 17 of various shapes can beremovably mounted so as to fit various types of workpieces W. Thus, itis possible to prepare for making a change in production or introducinga new model concurrently while the cleaning apparatus 10 is inoperation.

That is, the holding devices 17 holding the workpiece W needs to bevariously designed in accordance with the shapes of the workpieces W.Furthermore, in the case where a method (mixed production method) forsimultaneously producing a plurality of types of workpieces W is used,when the shape or type of the workpiece W is changed, the holding device17 needs replacement. The coupling device 48 enables the automaticreplacement of the holding devices 17 by preparing a plurality of theholding devices 17 to be attached to the feeding head of the feedingdevice 40 and attaching/detaching the various holding devices 17 to/fromthe cleaning apparatus 10 in accordance with the workpiece W flowing ina production line. Therefore, also in the mixed production method, theneed for operations for replacing the holding device 17 can beeliminated, and the productivity can be improved.

Referring to FIG. 3, the holding device 17 will be described. Theholding device 17 includes a frame 90, and the fluid pressure cylinder68, a seating pin 92, a positioning pin 93, and a fluid nozzle 69 forseating detection which are fixed to the frame 90. The fluid pressurecylinder 68 and the fluid nozzle 69 for seating detection are suppliedwith pressure fluid through the fluid coupling 67. The fluid pressureacting on each device is controlled in supply and reduction by the valveunit 63.

The workpiece W is seated on the frame 90 by a plurality of the seatingpins 92 and positioned on a seating face by the positioning pin 93. Aclamper 91 is attached to a piston shaft of the fluid pressure cylinder68, and opens and closes in response to the movement of the pistonshaft. When the clamper 91 is closed, the workpiece W is fixed to theseating face. The fluid nozzle 69 is installed on the seating face forthe workpiece W, and closed when the workpiece W is seated. When thefluid nozzle 69 is closed in response to the seating of the workpiece W,the pressure in the first fluid passage 64 connected to the fluid nozzle69 rises near a supply pressure. Thus, the seating of the workpiece Wcan be detected by a pressure switch 94. It should be noted that apressure sensor may be used in place of the pressure switch 94.

The cleaning chamber 15 provides the space (cleaning region E and workregion E) for cleaning (including operations such as air blowing anddeburring) the workpiece W by jetting cleaning liquid. The cleaningchamber 15 is brought into close contact with the bed 11 to shield itsinside from the outside of the cleaning apparatus 10. The shieldingfunction of the cleaning chamber 15 prevents cleaning liquid fromleaking to the outside of the cleaning apparatus 10. The cleaningchamber 15 includes a carry-in entrance 16 (see FIG. 2) for carrying inthe workpiece W from the outside. The carry-in entrance 16 is sealed bya carry-in door 19.

The cleaning tank 20 constituting the cleaning region E serving as thework region is fixedly installed within the cleaning chamber 15.Referring to FIGS. 5 and 6, the cleaning tank 20 and high-pressurecleaning will be described. A drain outlet 26 and a drain valve 24 aredisposed at the bottom of the cleaning tank 20. The drain valve 24 opensand closes the drain outlet 26. The drain outlet 26 is sufficientlylarge relative to the capacity of the cleaning tank 20, thereby allowingconsiderable reduction in drain time and contributing to shortening ofcleaning time. Because the drain valve 24 is installed so as to open andclose the drain outlet 26, the cleaning tank 20 can be filled withcleaning liquid. The drain valve 24 allows the filling of the cleaningtank 20 with cleaning liquid and the discharge of cleaning liquid, andtherefore the cleaning apparatus 10 can selectively perform in-aircleaning and in-water cleaning.

During in-water cleaning, chips or burrs falling from the workpiece Wcan float on cleaning water in the cleaning tank 20. These chips orburrs can redeposit on the workpiece W while the liquid level ofcleaning liquid is lowered in draining. Because the drain valve 24 issufficiently large relative to the volume of the cleaning tank 20, thelowering of the liquid level of cleaning liquid in draining isaccelerated. Thus, the redeposition of the chips or burrs on theworkpiece W is reduced.

A water supply pipe 23 communicates with a clean tank 35 (see FIG. 6A).A water supply valve 36 is provided at an inlet port of the water supplypipe 23. The water supply valve 36 is normally closed, and opened onlyduring water supply. When the water supply valve 36 is opened, thecleaning liquid filled in the clean tank 35 flows into the cleaning tank20 under the action of the water pressure. The cleaning tank 20 isprovided with a liquid level gauge (not shown). And when a “FULL” waterlevel is detected, the water supply valve 36 is closed. If the waterlevel of the clean tank 35 is set high, water supply is performed by thewater pressure in the clean tank 35, so that the structure can besimplified.

It should be noted that, a timer may be provided in place ofinstallation of the liquid level gauge for controlling the valve-openingtime of the water supply valve 36 so that the water supply valve 36 canbe opened only when the cleaning tank 20 becomes the full water level.

A high-pressure pump 27 pressurizes cleaning liquid in the clean tank 35to the range of 10 to 100 MPa. The pressurized cleaning liquid is sentthrough a cleaning liquid passage 29, and distributed among nozzleblocks 21 a to 21 f by a valve unit 28. The valve unit 28 is providedwith opening/closing valves 28 a to 28 g whose number is the same as thedistribution number. The opening/closing valves 28 a to 28 f communicatewith the nozzle blocks 21 a to 21 f through cleaning liquid passages 29a to 29 f, respectively. Cleaning nozzles 22 a to 22 f are disposed onthe nozzle blocks 21 a to 21 f, respectively. Each of the nozzle blocks21 is disposed on a side surface of the cleaning tank 20 and jets Ja toJf can be jetted from the cleaning nozzles 22 a to 22 f, respectively,in a plurality of directions from a plurality of surfaces. Becausecleaning liquid can be simultaneously jetted from the many cleaningnozzles 22 (nozzle groups 22 a to 22 f), a large number of jets aregenerated in the cleaning tank 20. The opening/closing valve 28 gcommunicates with a cleaning lance 25 through a cleaning liquid passage29 g.

Jetting is performed by dividing the cleaning nozzle groups 22 into aplurality of cleaning paths, thereby allowing a reduction in the amountof cleaning liquid to be simultaneously jetted. The cleaning nozzlegroups 22 are arranged so as to conform to the shape of the workpiece W,thereby allowing efficient cleaning of the workpiece W. The arrangementof the many cleaning nozzles 22 causes an increase in the necessaryelectric capacity of the high-pressure pump 27. By dividing the cleaningnozzles 22 into a plurality of groups and sequentially performingjetting for each group, the necessary electric capacity of thehigh-pressure pump 27 can be reduced.

Referring to FIG. 7, the cleaning lance 25 will be described. Thecleaning lance 25 has a vertically-elongated shaft to horizontally jethigh-pressure water from a tip of the shaft. The cleaning lance 25 isjournaled to the vicinity of a lower surface of the cleaning tank 20. Inthe case of using the cleaning lance 25, the cleaning lance 25 issupplied with high-pressure water for rotation. Thereafter, a holeportion H of the workpiece W is positioned above the cleaning lance 25so that the axis of the hole portion H is aligned with a rotating shaftof the cleaning lance 25 (see FIG. 7A). Then the orthogonal movingdevice 70 moves the workpiece W downward so that the cleaning lance 25is inserted into the hole portion H (see FIG. 7B). After the completionof cleaning, the workpiece W is moved upward so that the cleaning lance25 is removed from the workpiece W. The cleaning lance 25 passes throughthe inside of the hole portion H of the workpiece W while rotating,thereby performing cleaning of the inside of the hole portions H or ahole crossing the hole portion H. Furthermore, the cleaning lance 25 canremove burrs by directing high-pressure water onto burrs on the crossinghole in the hole portion H.

It should be noted that the cleaning tank 20 is unnecessary if cleaningin water (in-water cleaning) of the workpiece W is not performed. In thecase of not including the cleaning tank 20 in the cleaning chamber 15,the cleaning nozzles 22 or the cleaning lance 25 is directly disposedwithin the cleaning chamber 15. In this case, the region surrounded bythe cleaning nozzle groups 22 serves as the cleaning region E.

Furthermore, although the single cleaning lance 25 is disposed so as toextend vertically from a lower portion of the cleaning tank 20, thedirection and number of installation of the cleaning lance 25 may bechanged as appropriate according to the size of the workpiece W, thenumber of workpieces W held by the holding device 17, and theinstallation method of the cleaning nozzles 22. For example, the samenumber of the cleaning lances 25 as the number of the workpieces W heldby the holding device 17 may be installed.

As shown in FIG. 1, within the cleaning chamber 15, air blow pipes 30are fixedly installed on the bed 11. The air blow pipes 30 form arectangular frame and are mounted with a plurality of air blow nozzles31 and 34 facing the inside of the air blow pipes 30. An air blow pipe32 communicates with the air blow pipes 30. Dry air for air blowing ispressurized by a blower 33 to be supplied to the air blow nozzles 31 and34 through the air blow pipe 32.

It should be noted that compressed air may be used in place of air sentfrom the blower 33 as dry air for air blowing. Furthermore, pipenozzles, broom nozzles, or knife nozzles may be used as the air blownozzles 31 and 34.

The cleaning apparatus 10 according to the embodiment of the presentinvention holds the workpiece W outside the cleaning chamber 15 with theholding device 17 disposed at the leading end (feeding head) of thefeeding device 40. Then the cleaning apparatus 10 takes the workpiece Winto the cleaning region E in the cleaning chamber 15 through thecarry-in entrance 16 (see FIG. 2) while holding the workpiece W. Thecleaning apparatus 10 properly controls the position and attitude of theworkpiece W in the cleaning chamber 15 with the orthogonal moving device70 so that the workpiece W is directed toward the cleaning nozzles 22fixedly installed within the cleaning chamber 15. The cleaning nozzles22 jet cleaning liquid to clean the workpiece W directed toward thecleaning nozzle 22 with the jets Ja to Jf (see FIG. 6) of cleaningliquid.

Because the feeding device 40 holds the workpiece W outside the cleaningapparatus 10 and carries it into the cleaning region E, a device forcarrying the workpiece W into the cleaning apparatus 10 is unnecessary.Therefore, the cleaning apparatus 10 can be very easily incorporatedinto the process line.

Because the many cleaning nozzles 22 are installed on the nozzle block21, the cleaning apparatus 10 can simultaneously clean many portions tobe cleaned of the workpiece W, thereby allowing shortening of cleaningtime. If the nozzle block 21 is designed for the shape of the workpieceW, cleaning of necessary portions to be cleaned can be completed just bymoving the workpiece W to designed attitude and position several times.

The many air blow nozzles 31 and 34 are arranged inside the air blowpipes 30 formed in the rectangular frame shape. Thus, almost all ofcleaning liquid adhering to the workpiece W can be removed just bycausing the workpiece W to pass through the inside of the air blow pipes30.

Because the cleaning apparatus 10 is driven by the numerical controldevice, a cleaning program can be easily created.

Moreover, in the case of moving the cleaning nozzles 22, a liquid supplyunit that supplies high-pressure cleaning liquid to the cleaning nozzles22 needs to include a flexible hose, a fluid supply rotary joint andother movable portions so as to cope with the movement of the cleaningnozzles 22. In this case, the liquid supply unit needs to be designed toprevent its interference with a moving device for the cleaning nozzles22 and prevent its contact with high-pressure jets jetted from thecleaning nozzles 22, leading to increased design restrictions and thecomplexity of the device.

On the other hand, however, in the cleaning apparatus 10 according tothis embodiment, the cleaning nozzles 22 are fixedly installed, andtherefore the construction of the liquid supply unit can be simplified.Furthermore, the cleaning liquid passage 29 can be fixed, therebyincreasing the flexibility in its design.

In the case of moving the cleaning nozzles 22, it is necessary to embedthe liquid supply unit inside the nozzle moving device. Inside thenozzle moving device, the size and movable range are restricted. Theelements, such as pipes and joints, constituting the liquid supply unithave restrictions on supply flow rate and supply pressure, and once theyare designed, changes in supply flow rate and supply pressure are noteasy. In the cleaning apparatus 10 according to this embodiment, theliquid supply unit can be fixed, and therefore the supply flow rate andsupply pressure can be easily changed. Consequently, the cleaningapparatus 10 can be easily employed for ultrahigh-pressure cleaning orlarge flow cleaning.

Further, the orthogonal moving device 70 allows the workpiece W to movein a free attitude. In the case of deburring the workpiece W, it isnecessary to direct jets onto burrs in such a manner that the jets goover the area of the workpiece W where burrs are generated. Because theorthogonal moving device 70 is used as the moving device, thepositioning accuracy, repeatability, or locus accuracy of the workpieceW can be set high as compared with the multi-joint robot composed of thecombination of rotation nodes. Thus, high deburring performance can beobtained. In addition, in the case of inserting the workpiece W into thecleaning lance 25, even if the clearance between the cleaning lance 25and the workpiece W is small, the interference therebetween can beprevented.

Furthermore, the cleaning apparatus 10 of this embodiment includes theorthogonal moving device 70 as the moving device, and thus is easy touse for an operator under simple control.

In the case where the workpiece W as a heavy object is held by themulti-joint robot, a large centrifugal force acts on the rotating shaftconstituting the multi-joint robot, and thereby not allowing swinging ofthe workpiece W at a high speed.

On the other hand, the cleaning apparatus 10 of this embodiment includesthe orthogonal moving device 70 as the moving device, thereby allowingswinging of the workpiece W at a high speed. In the cleaning apparatus10 of this embodiment, the many cleaning nozzles 22 are arranged on thefour surfaces. Thus, by moving up and down while swinging the workpieceW, a wide surface can be subjected to high-pressure cleaning at a timeand a high cleaning effect can be obtained in a short cleaning time.

The cleaning apparatus 10 swings and moves the workpiece W with thefeeding device 40. Therefore, a large space and stroke for movement isrequired. The orthogonal moving device 70 is constructed such that the Zsaddle 85 is disposed on the moving column 78 and the Y saddle 84 isdisposed on the Z saddle 85, thereby allowing less arrangement space.Furthermore, because the moving column 78 has a large dimension andincludes the large workpiece W and the feeding device 40 at its leadingend, a large load is applied to the X axis and the moving column 78. Thecleaning apparatus 10 includes the two X-axis driving devices 71 and 75for synchronously driving the upper and lower portions of the movingcolumn 78, thereby suppressing the distortion of the moving column 78,lowering the rigidity of the moving column 78 and the bed 11, andallowing miniaturization of the cleaning apparatus 10. Additionally, theincrease in size of the moving device is facilitated.

The feeding device 40 according to the embodiment of the presentinvention can rotate the holding device 17 holding the workpiece W withthe first rotary saddle 59 and the second rotary saddle 47, whichconstitute the two-axis rotating shafts perpendicular to each other.Thus, the feeding device 40 can freely select the attitude of theworkpiece W. Therefore proper cleaning operation even can be performedfor the workpiece W having a complicated shape, so that the amount offoreign matters left on the workpiece W can be reduced. Furthermore,while in the case of removing a burr adhering to the workpiece W, it isnecessary to direct high-pressure jets onto the burr at an anglesuitable for the burr, and the feeding device 40 allows a free attitudeof the workpiece W, thereby allowing removal of the burr adhering to asurface of the workpiece W having a complicated shape.

The planetary gear 58 is mounted to a leading end of the driving system,thereby reducing backlash of the first rotary saddle 59, and theplanetary gear 46 is mounted to a leading end of the driving system,thereby reducing backlash of the second rotary saddle 47. Thus, theattitude of the workpiece W can be precisely controlled.

The cleaning nozzles 22 are fixed to the cleaning tank 20, and thus canbe accurately positioned with respect to the workpiece driving device13. Furthermore, the cleaning nozzles 22 are less susceptible tovibrations of the moving portions. Therefore, the relative position ofthe workpiece W, which is moved with high positional accuracy by theworkpiece driving device 13, and the cleaning nozzles 22 accuratelymatches with a programmed position.

The constructions being such that the position and attitude of theworkpiece W are precisely controlled and being such that the cleaningnozzles 22 are positioned with high assembling accuracy and are lesssusceptible to vibrations combine to give a high cleaning and deburringcapacity to the cleaning apparatus 10 of this embodiment.

The servomotor 49 serving as the first driving device and the servomotor41 serving as the second driving device are disposed outward of thecover device 14 with respect to the cleaning region E. Moreover,mechanical elements for transmitting the driving force of theservomotors 49 and 41 are disposed inside the feed base 55, andtherefore isolated from the cleaning region E.

Thus, the servomotors 49 and 41, and the drive power transmission systemare prevented from coming into contact with jets or vapors of cleaningliquid. Therefore, durability can be given to the feeding device 40, theworkpiece driving device 13, or the cleaning apparatus 10 of thisembodiment.

The holding device 17 or the coupling device 48 is exposed tohigh-pressure jets and high-temperature vapor. In general, electriccomponents have poor resistance thereto because they have contacts.Furthermore, damage of an electric-wire protector causes an electricshort, leading to breakage. Because the holding device 17 holds andswings the workpiece W, damage of the holding device 17 might exert acritical adverse influence on the whole apparatus. In the case of theholding device 17 or the coupling device 48 including electricalcomponents, the fluid is supplied as the driving source thereof, andtherefore the reliability of the holding device 17 is enhanced.

While an embodiment of the present invention has been described above,the invention is not limited to the above-described embodiment, andspecifications can be changed as appropriate. For example, although inthe above-described embodiment, the workpiece W is used as the object,the invention is not limited thereto, but also a nozzle or a workingtool can be used as the object. Furthermore, although the feeding device40 according to the present invention is mounted on the cleaningapparatus 10, the invention is not limited thereto, but is applicable tovarious machine tools or processing tools.

For example, a decompression container having an opening may be providedin place of the air blowing region serving as the work region E forcommunication between itself and a pressure reducing pump. On the otherhand, a sealing cover for sealing the opening of the decompressioncontainer is provided on the holding device 17. The feeding device 40puts the workpiece W after cleaning into the decompression containerthrough the opening. The opening of the decompression container issealed with the sealing cover of the holding device 17. Then, when thecoupling device 48 is released, the workpiece W is held within thedecompression container sealed with the sealing cover of the holdingdevice 17. When the pressure in the decompression container is reducedby the pressure reducing pump and becomes lower than the vapor pressureof the left cleaning liquid, the cleaning liquid adhering to theworkpiece W is vaporized and the workpiece W is dried. The feedingdevice 40 released from the coupling device 48 is coupled to the otherholding device 17A, and then the holding device 17A holds the otherworkpiece W to be cleaned in the cleaning region E. With thisconstruction, while the workpiece W is dried under reduced pressure, theother workpiece W can be held to be cleaned.

What is claimed is:
 1. A feeding device movably disposed through a coverdevice so as to face a work region shielded by the cover device, forholding an object and controlling an attitude of the object, comprising:a first rotary saddle that is rotatable about a first axis; a secondrotary saddle that is disposed on the first rotary saddle and rotatableabout a second axis in a direction different from the first axis; aholding device that is disposed on the second rotary saddle to hold theobject; a first driving device that is disposed outward of the coverdevice with respect to the work region to rotate the first rotarysaddle; a second driving device that is disposed outward of the coverdevice with respect to the work region to rotate the second rotarysaddle, a feed base that supports the first and second driving devices,the feed base having a hollow portion; a first transmission shaft thatis disposed inside the hollow portion and coupled to the first drivingdevice; a first reduction gear mechanism that decelerates rotation ofthe first transmission shaft and outputs the decelerated rotation, thefirst reduction gear mechanism having a first output shaft formed of ahollow shaft; a second transmission shaft that is disposed through thefirst output shaft, the second transmission shaft being disposedparallel to the first axis inside the hollow portion and coupled to thesecond driving device; and a second reduction gear mechanism thatdecelerates rotation of the second transmission shaft and outputs thedecelerated rotation, the second reduction gear mechanism having asecond output shaft coaxial with the second axis, wherein the firstrotary saddle is fixed to the first output shaft and rotatably journaledto the second transmission shaft, and the second rotary saddle is fixedto the second output shaft.
 2. The feeding device according to claim 1,wherein the first reduction gear mechanism includes: a small-diametergear fixed to the first transmission shaft; a large-diameter gear havinga meshing engagement with the small-diameter gear, the large-diametergear being disposed coaxially with the second transmission shaft; and afirst reduction gear coaxially coupled to the large-diameter gear fordecelerating rotation of the large-diameter gear.
 3. The feeding deviceaccording to claim 2, wherein the holding device has: a fluid pressurecylinder that holds the object; and a fluid supply unit that suppliespressure fluid from a fluid supply source to the fluid pressurecylinder, and the fluid supply unit includes: a first fluid supplyrotary joint that is disposed on the first rotary saddle; a second fluidsupply rotary joint that is disposed on the second rotary saddle; afirst fluid passage that supplies pressure fluid from the fluid supplysource to the first fluid supply rotary joint; a second fluid passagethat supplies pressure fluid from the first fluid supply rotary joint tothe second fluid supply rotary joint; and a third fluid passage thatsupplies pressure fluid from the second fluid supply rotary joint to thefluid pressure cylinder.
 4. An object driving device having the feedingdevice according to claim 3, a moving device for movably supporting thefeeding device, and a bed for supporting the moving device, the movingdevice comprising: a horizontal movement guide mechanism that is placedon the bed; a moving column that is movably supported by the horizontalmovement guide mechanism; an X-axis driving device that horizontallymoves the moving column; a vertical movement guide mechanism that isdisposed on the moving column; a Z-axis saddle that is movably supportedby the vertical movement guide mechanism; and a longitudinal movementguide mechanism that is disposed on the Z-axis saddle to longitudinallymovably support the feeding device, the moving device being disposedoutward of the cover device with respect to the work region.
 5. Thefeeding device according to claim 1, wherein the first and secondtransmission shafts are arranged adjacent and parallel to each other,and the second reduction gear mechanism includes: a first bevel gearfixed to the second transmission shaft; a second bevel gear having ameshing engagement with the first bevel gear, the second bevel gearbeing disposed coaxially with the second axis; and a second reductiongear coaxially coupled to the second bevel gear for deceleratingrotation of the second bevel gear.
 6. The feeding device according toclaim 5, wherein the holding device has: a fluid pressure cylinder thatholds the object; and a fluid supply unit that supplies pressure fluidfrom a fluid supply source to the fluid pressure cylinder, and the fluidsupply unit includes: a first fluid supply rotary joint that is disposedon the first rotary saddle; a second fluid supply rotary joint that isdisposed on the second rotary saddle; a first fluid passage thatsupplies pressure fluid from the fluid supply source to the first fluidsupply rotary joint; a second fluid passage that supplies pressure fluidfrom the first fluid supply rotary joint to the second fluid supplyrotary joint; and a third fluid passage that supplies pressure fluidfrom the second fluid supply rotary joint to the fluid pressurecylinder.
 7. An object driving device having the feeding deviceaccording to claim 6, a moving device for movably supporting the feedingdevice, and a bed for supporting the moving device, the moving devicecomprising: a horizontal movement guide mechanism that is placed on thebed; a moving column that is movably supported by the horizontalmovement guide mechanism; an X-axis driving device that horizontallymoves the moving column; a vertical movement guide mechanism that isdisposed on the moving column; a Z-axis saddle that is movably supportedby the vertical movement guide mechanism; and a longitudinal movementguide mechanism that is disposed on the Z-axis saddle to longitudinallymovably support the feeding device, the moving device being disposedoutward of the cover device with respect to the work region.